Development of a Parameterized Passenger Vehicle Model for Longitudinal Dynamics for a Desktop Driving Simulator

Driving Simulators are an important research tool in the automotive field. They are used to simulate and verify interactions between vehicles and drivers in a realistic as well as conditioned traffic environment. Real vehicle testing and pure simulation (using a driver model) are two alternative tools of collecting such information. In essence, driver simulators are especially valuable in gauging drivers action and perception, which cannot be adequately simulated or are less suitable in testing in real vehicles.
Adequate and accurate vehicle model, representative of the real vehicle behaviour in different driving conditions, is needed. However, to model a certain vehicle is a non-trivial, expensive and time-consuming task. Advanced driver simulators are present in Sweden, especially kept by VTI in Göteborg and Linköping, which provide very realistic driver experience and perception and they simulate, very accurately, a real-time scenario in a holistic environment.
But, in the modern world, vehicle and traffic situations have become so complex that the application and usefulness of driving simulators has moved beyond its usual definition. Thus, every experiment goes through an intricate, time-consuming and thus expensive process of experimental design and development. The solution proposed in this master thesis is a Desktop Driving Simulator, located at Chalmers University of Technology, in Göteborg, which is portable and can simulate an experiment/scenario at an office level before moving to advanced simulators or moving to test track.
Moreover, the thesis describes the hardware of the Desktop Driving Simulator and its software system in a very detailed.
Several simulations were performed, also with an Anti-lock braking system (ABS)-equipped vehicle. It is used in the modern cars to prevent the wheels from locking after brakes are applied. To be able to run a simulation with this system and study the braking performance, an ABS system was modelled. Particularly, the ABS subsystem in Simulink included in the S2 vehicle model, located at Chalmers University of Technology, was fitted in the original Vehicle Dynamics Model of this thesis.
The vehicle model was parameterized for a passenger vehicle, such as a Volvo S40 (1.6 ton). Different cases were analized, performing offline and online simulations in order to make some considerations on driver behaviour and influence. The offline simulations are obtained only using MATLAB and Simulink, while the online ones are performed driving the Desktop Driving Simulator.
However, results obtained will not be at par with analysis on advanced simulators, especially regarding driver perception and response, but may provide an indication towards its behaviour and relevance.
From the experiments, it was possible to detect that the offline and online simulations performed are roughly equal, show the same behavior, except for the initial delay and some interference driving the simulator.
Anyhow, the thesis can be considered a very stable base for further model tuning and future tests. With its modular structure and small manual, it can be considered as a good starting point for future improvement of the whole simulator system.

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1 Introduction
Driving Simulators represent an important tool to simulate different driving
vehicles in a realistic way.
Essentially, they are used to verify drivers behavior and perception, which
cannot be simulated in testing in real vehicles.
Data collection from real vehicle testing is a not trivial, expensive and time-
consuming task. There are some advanced simulators in Sweden, especially
kept by VTI in Göteborg and Linköping, that allow to simulate an experiment
in real-time.
Nowadays, driving real vehicle on the road in a safe way has become
complicated for many reasons, so using a driving simulator is becoming really
significant. Every test needs a long and complex process of simulation and
validation. Indeed, a big amount of time in Driving Simulators is often used for
debugging/changing the experiment. The solution adopted in this project is a
Desktop Driving Simulator, which can simulate an experiment/scenario at an
office level before moving to more advanced simulators or moving to test track.
However, results obtained cannot be exactly compared with those of advanced
simulators, especially regarding drivers behaviour, but at least they could
provide some indications.
1.1 Driving Simulator and its role
One of the most common and universal tasks people perform every day is
driving. It seems a really ordinary action, but it actually needs all of cognitive,
perceptual, sensory and motor functions.
Different experimental studies can always be performed with real vehicle on-
road tests, but using a Driving Simulator is better for several reasons, such as
safety and cheapness. Moreover, it gives measures of driver behavior that are
repeatable and objective, it allows for complete control of the driving
environment and finally it can be managed in a laboratory setting.
Driving simulation is a really powerful tool in the automotive field, but it also
other areas of research, such as vehicle dynamics, motion cueing, sound and
graphics rendering and much more are involved. Moreover, the studies about
the Driving Simulators apply to many areas of transportation research, like
road, infrastructure and vehicle design, but also human factors, driver
interaction with the vehicle (for instance steering or braking) and the traffic
environment.
The main advantages of Driving Simulator are listed below:
 repeatability in the experiments: this factor gives the possibility to
collect data that may take much longer time in a real life driving